Percussive device



July 5, 192 7.

A. I. WOODRING PERCUSSIVE DEVICE Filed Feb. 15, 1926 Inventor. A.W00d7"ir?g, 5g

Patented July 5, 1927.

I UNITED STATES PATENT OFFICE- SAFETY DE- VICES COMPANY, OF WATERLOO,IOWA.

PERCUSSIVE DEVICE.

Application fiIed'February 13, 1926. Serial No. 88,143.

My invention relates to improvements in percussive devlces, and theobject. of my 1111- provement is to supply a simple, easily con' withoutdeparting from the spirit of the in vention.

In said drawings, Fig 1 is a full sized View of my percussive device,includingits manually and resiliently controlled. operating valve, partsbeing shown in side elevation and parts in medial vertical longitudinalsection or broken away, the dotted lines in-' dicat-inga changedoperative position of the percussor. Fig. 2 is a. plan view of thepercussive device alone, the full and dotted outlines of the percussorindicating opposite limits of travel thereof with relation to theperiphery of an apposed gong.

The device is particularly appropriate for employment as a soundingwarning signal upon a vehicle, such as'a street-car or the like, and isintended and designed for using compressed air or other fluid underpressure for its motive power. I

The percussive device comprises a hollow cylinder I which is open at oneend and closed at the other, but the closed end has a relatively smallinlet-port 5 in the cylinder boss 4, ,and which communicates with athreaded socket of larger bore 6 in said boss, the latter receiving athreaded nipple 7 from an elbow-coupling 8 which communicates with apipe 9, and the latter by an elbow coupling 10, pipe 11 and: threadednipple 12' communicates with a supply-port or passage 36 leading from acentral chamber 35 in a valve chamber 27. I

The operating valve-chamber 27, while included in the combination ofthisinvention,

is not specifically claimed or particularly described herein, beingotherwise patented in my United States Patent No. 1,511,554 of October14, 192-1.

The cylinder 1 has and is supported de pendingly upon hangers 2 from anysupport. A cup-shaped plunger '13 is fitted within and to reciprocatewithin the interior hollow 30f the cylinder 1, and has a front closingwall 17 for the open end of the cylinder with an annular stop 18 whichat one limit of reciprocation contacts with thefront end of thecylinder. This annular end part 18 terminates in a frustal part 19 whichserves as an interior centering member for one end of a coiledcompression spring21 which is mounted around a diminished hammer part 20and engaged between said annular part 18 and the inner wall of aU-shaped bracketnnember 22, whose end parts embrace opposite sides ofthe cylinder body in fitting flattened bosses 25 thereon and is securedby set-screws 24. The hammer part 20 traverses a bearing-aperture 23 inthe cross-part oft-he member 22 to project therebeyondtoward andordinarily spaced from the edge ofa resonant gong 26. The interspace issuch, that at its outer, limit of reciprocation, the hammer 20 contactsimpactingly with said gong.

A number of radial holes 14 are made in the plunger wall 13 about midwayof its length to the central hollow 16 of the plunger and terminateoutwardly in a shallow annular groove 15 around the plunger at thatlocation, and a narrow seepage passage 45- 16.

Referring now to the operating valvechamber 27, it has a passage 28,interiorly threaded, for communication with some conduit to a supply ofair or other suitable fluid under compression but not shown. In thelower part of the valve-chamber is a lower against the lower part of thelatter tending to keep the valve 31 closed. The upper part of thevalve-body which traverses said passage 34 terminates upwardly in ashort finger-or'boss 37 which when in its upper position is spaced'fromthe lower end of the loo bore 39- of a plunger 40whosenpper part isseated in a bearing opening in the upper part of the valve-chamber toproject outwardly therefrom, the bore 39 turning laterally intocommunication with the atmosphere when the plunger is up. A pair ofarched standards ll. have a pintle on which is pivoted a pedal sl twhich has its lower edge shaped as a cam it to contact with the plungerFlt-l.

To ring the gong 26, the pedal 4:3 deprea ed with the plunger il whichpushes down the valve parts 237 231, and compressed air passes throughthe chamber 35 and conduit 9 to the cylinder 1. The plunger 13 is pushedoutwardly to expose the annularly connected ports 14, while the spring21 is comtircssed, and the hammer 2t rings the gong .26. The air escapesmore rapidly through the ports l-l. than it enters through the inlet l,so that the cylinder is immediately emptied ot air to about atmosphericpres sure. The quick escape of the cylinder air through the ports 1st isexpedited by the use ol the eircunt'tercntial groove it), as the advancing edge of the latter opens the groove all around at once with awide delivery opening for the ports ll, which could not occur withoutsome delay were the groove omitted. for in the latter case but a smallarea of each port would be opened instantly, the response of the plungerin reversing being delayed. The spring 21 returns the plunger closingthe ports I l.

The narrow grooves do a n in the plunger 13 and its fillet 18 areprovided to permit a slight seepage of air from the cylinder and isuseful in case of a small leakage of air hrough the operating valve,n'evenling the building up in the cylinder oi air prc sure from suchleakage between outward reciprocations or when the valve or any othertype ol operating valve is leaky.

In the valve-chamber 27, the plunger eltl has an annular flange andbetween this l'lange and the bottom of the chamber 35 is mounted acoiled spring which, when the pedal L3 is released. lifts the plunge andby the bore 39 exhausts the air from the chan'iber 35. so that the lowerspring 312 may return the valve 31 to its seat.

It should be noted, that no portion oi the outer atmosphere can enterthe cylinder 1, becaure the ports 1-lcan pass only com pressed air fromthe cylinder out throtuzh the plunger, tor the quick closing of theports on the return stroke prevents admission oi the outer air and thusno atmo pheric dust can pass into the cylinder as in some other kinds oflike devices. to toul the cyl-v inder and gradually render itinoperative.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is:

1. In a device of the character described, a cylinder having an open anda closed end,

nee r927 the latter having a relatively small inlet port in controlledcommunication with a source ol fluid under pressure, a cupshaped plungertitted within and to recipro ate in said cylinder and having an outerstriket stem, a compression spring anchored to resiliently engage theouter end of said plunger, said plunger having a medial groove around itand having holes leading from said groove to the interior of theplunger, the open end of the plunger being in communication with thecavity oil the cylinder, said groove filling with fluid undercompression to exhaust the tluid quickly when the groove is uncovered inthe outward movement of the plunger, the spring reacting to return theplunger to close said groove upon partial exhaustion of the fluid undercompression in the cylinder cavity, whereby the spring is kept inpartial compression during the reciprocations of the plunger, and thereeiprocations of the plunger are limited in their length toapproximately the width of said groove to produce rapid blows by thesaid striker stem upon a resonant device.

In a device of the character described, a cylinder having an open and aclosed end, the latter having a relatively small inlet: port incontrolled communication with a source of lluid under pressure, acup-shaped plunger titted within and to reciprocate in said cylindcr andhaving an outer striker stem, a eon1- pression spring anchored toresiliently engage the outer end of the plunger, said plunger having amedial groove around it and having holes leading from said groove to theinterior of the plunger, the open end of the plunger being incoinnniinication With the cavity of the cylinder and the plunger havinga minute longitudinal groove leading from said medial groove outwardlyfor con stant communication with the atmosphere, said medial groovefilling with fluid under compression to exhaust the fluid quickly whenthe groove is uncovered in the outward niovei'ncnt of the plunger, thespring reacting to return the plunger to close said groove upon partialexhaustion oi? the fluid under compression in the cylinder cavity,whereby the spring is kept under partial COYHPIGS- siou during thereciprocations of the plunger, and the reciproeationa of the plunger arelimited in their length to t 'avel approxh mately the width of saidgroove in opening and closing it, to thereby produce rapid blows by thestriker stem upon a resonant device.

In testimony whereof I aflix my signaturc.

ALBERTO I. VVOODRING.

